Summary of the invention
The object of the present invention is to provide a kind of current in wire measuring device and methods, and volume and preparation cost are low, convenient for peaceDress, and temperature drift is small, high sensitivity.
In order to solve the above technical problems, the present invention provides a kind of current in wire measuring device, including shell, it further include settingBe placed in the intracorporal magnetic vector for measuring conducting wire x-axis direction to be measured of the shell the one-dimensional magnetoresistive chip of x-axis, with the x-axisOne-dimensional magnetoresistive chip is in same position and the y-axis One-Dimension Magnetic of vertical distribution, magnetic vector for measuring conducting wire y-axis to be measured directionHinder chip, ADC module and control module, in which:
The first input end of the ADC module is connect with the output end of the one-dimensional magnetoresistive chip of the x-axis, the second input terminal withThe output end of the one-dimensional magnetoresistive chip of y-axis connects；
The input terminal of the control module is connect with the first output end and second output terminal of the ADC module respectively, is usedIn the distance between center of circle according to Biot-Savart law, the one-dimensional magnetoresistive chip of the x-axis and the conducting wire to be measured, conversionThe current value of the conducting wire to be measured is obtained for the magnetic vector of the x-axis direction of digital quantity and the magnetic vector in y-axis direction.
Preferably, when a point of the conducting wire to be measured and the shell is tangent, the main control module is also used to basisThe pre-determined distance of preset of the one-dimensional magnetoresistive chip of x-axis to the shell, the preset to point of contact distance, be converted toThe magnetic vector of the x-axis direction of digital quantity and the magnetic vector in y-axis direction obtain the wire cross-section area to be measured；
Wherein, the center of circle of the preset, the point of contact and the conducting wire to be measured is point-blank；The x-axis is one-dimensionalThe center of circle of the preset and conducting wire to be measured of the place straight line and shell of the preset of magnetoresistive chip and the shellPlace straight line is vertical.
Preferably, further includes:
First be set between the output end of the one-dimensional magnetoresistive chip of the x-axis and the first input end of the ADC moduleAmplifier is amplified for the magnetic vector to x-axis direction；
Second be set between the output end of the one-dimensional magnetoresistive chip of the y-axis and the second input terminal of the ADC moduleAmplifier is amplified for the magnetic vector to y-axis direction.
Preferably, further includes:
It is set on the shell, for the conducting wire to be measured to be fixed fixation device on the housing.
Preferably, the fixed device is U-shaped buckle.
Preferably, Open Side Down for the U-shaped buckle, a port of the U-shaped buckle and the housing hinge, anotherA port is detachably connected with the shell.
Preferably, the shell is equipped with and the mutually matched inner concave of conducting wire to be measured.
Preferably, the U-shaped buckle is the Elastic buckle of opening upwards.
Preferably, the U-shaped buckle is plastic buckle.
In order to solve the above technical problems, being applied to the present invention also provides a kind of current in wire measurement method such as above-mentioned instituteIn the current in wire measuring device stated, this method comprises:
The one-dimensional magnetoresistive chip of x-axis measures the magnetic vector of the x-axis direction of conducting wire to be measured, the one-dimensional magnetoresistive chip measurement of y-axis toSurvey the magnetic vector in the y-axis direction of conducting wire；
The magnetic vector of the x-axis direction is converted to digital quantity by analog quantity by ADC module, by the magnetic of the y axis directionField vector is converted to digital quantity by analog quantity；
Control module according to Biot-Savart law, the one-dimensional magnetoresistive chip of the x-axis and the conducting wire to be measured the center of circle itBetween distance, be converted to the magnetic vector of x-axis direction of digital quantity and the magnetic vector in y-axis direction obtains the conducting wire to be measuredCurrent value.
The application in view of one-dimensional magnetoresistive sensor have height can integrated level, high sensitivity, small size, cheap, small temperature drift,The wide advantage of measurement range, therefore, the application acquire conducting wire to be measured by two one-dimensional magnetoresistive chips of vertical distribution respectively and existMagnetic vector at magnetoresistive chip position (or could also say that the one-dimensional magnetic resistance core of y-axis in conjunction with the one-dimensional magnetoresistive chip of x-axisPiece) it cuts down your law with the distance between the center of circle of conducting wire to be measured and Biot-Sa and can obtain the current value of conducting wire to be measured, fromAnd make the volume of current in wire measuring device and preparation cost low, it is easily installed, and temperature drift is small, high sensitivity.
Specific embodiment
Core of the invention is to provide a kind of current in wire measuring device and method, and volume and preparation cost are low, convenient for peaceDress, and temperature drift is small, high sensitivity.
In order to make the object, technical scheme and advantages of the embodiment of the invention clearer, below in conjunction with the embodiment of the present inventionIn attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment isA part of the embodiment of the present invention, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the artEvery other embodiment obtained without making creative work, shall fall within the protection scope of the present invention.
Fig. 1 is please referred to, Fig. 1 is a kind of structural schematic diagram of current in wire measuring device provided by the invention, the device packetShell 1 is included, further includes the one-dimensional magnetic resistance of x-axis for being set to magnetic vector in shell 1, for measuring conducting wire x-axis direction to be measuredChip 2 and the one-dimensional magnetoresistive chip 2 of x-axis are in same position and vertical distribution, the magnetic field arrow for measuring conducting wire y-axis to be measured directionThe one-dimensional magnetoresistive chip 3 of the y-axis of amount, ADC module 4 and control module 5, in which:
The first input end of ADC module 4 is connect with the output end of the one-dimensional magnetoresistive chip 2 of x-axis, the second input terminal and y-axis oneTie up the output end connection of magnetoresistive chip 3；
The input terminal of control module 5 is connect with the first output end and second output terminal of ADC module 4 respectively, is used for basisThe distance between the one-dimensional magnetoresistive chip 2 of Biot-Savart law, x-axis and the center of circle of conducting wire to be measured are converted to the x-axis of digital quantityThe magnetic vector in direction and the magnetic vector in y-axis direction obtain the current value of conducting wire to be measured.
Specifically, in current in wire measuring device provided by the present application, measured provided with two one-dimensional magnetoresistive chips toThe magnetic vector of conducting wire is surveyed, the two one-dimensional magnetoresistive chips are respectively the one-dimensional magnetoresistive chip 2 of x-axis and the one-dimensional magnetoresistive chip 3 of y-axis,The one-dimensional magnetoresistive chip 2 of x-axis and the one-dimensional setting of magnetoresistive chip 3 of y-axis are at same position and orthogonal, to measure at the positionThe magnetic vector B of x-axis directionxWith the magnetic vector B in y-axis directiony.The application magnetoresistive chip 2 one-dimensional for x-axis and y-axis One-Dimension MagneticThe setting position of resistance chip 3 does not limit particularly, determines according to the actual situation.
(exist because the one-dimensional magnetoresistive chip 2 of x-axis and the one-dimensional magnetoresistive chip 3 of y-axis are arranged measuring the one-dimensional magnetoresistive chip 2 of x-axisAt same position, therefore, the one-dimensional magnetoresistive chip 3 of y-axis could also say that here) magnetic vector of the x-axis direction of positionBxWith the magnetic vector B in y-axis directionyAfterwards, ADC module 4 is by the magnetic vector B of x-axis directionxWith the magnetic vector B in y-axis directionyDigital quantity, magnetic vector B of the control module 5 in the x-axis direction for receiving digital quantity are converted to by analog quantityxWith y-axis directionMagnetic vector ByAfterwards in conjunction with the distance between the one-dimensional magnetoresistive chip 2 of x-axis and the center of circle of conducting wire to be measured, Biot-Savart lawObtain the current value of conducting wire to be measured.
In addition, it should be noted that, conducting wire can be understood as with current in wire measuring device it is a little tangent, in practical applicationIn, conducting wire to be measured only has very short one section tangent with current in wire measuring device, for convenience of calculating, can will survey with current in wireThat section of tangent conducting wire (cylindrical body of high very little) to be measured of amount device is understood as a face, the center of circle in this face namely the applicationThe center of circle mentioned.
According to Biot-Savart law, the magnetic vector of the available one-dimensional magnetoresistive chip 2 of x-axis are as follows:
Wherein, μ0For space permeability, value is 4 π × 10-7Tm/A, and d is the one-dimensional magnetoresistive chip 2 of x-axis and conducting wire to be measuredThe distance between the center of circle, can be previously obtained.
Again
Then
Referring to figure 2., Fig. 2 is provided by the invention a kind of to obtain the electric current of conducting wire to be measured using Biot-Savart lawThe schematic diagram of value.
Assuming that the electric current of conducting wire to be measured is I, radius is unknown, and conducting wire to be measured abuts current in wire measuring device, and O point isThe contact point (namely point of contact) of current in wire measuring device and conducting wire to be measured, A point be current in wire measuring device central point (Preset i.e. in the application), C point be the one-dimensional magnetoresistive chip 2 (or the one-dimensional magnetoresistive chip 3 of y-axis) of x-axis position, 3 points of AOBPoint-blank, the distance between AC l is it is known that setting the distance between AO, BO, BC is m, r, d respectively, wherein known to the value of m.The conducting wire can be directly measured in the magnetic field strength of C point, respectively B by twin shaft magnetoresistive chipxAnd By, then:
R value can be calculated by above formula, are as follows:
Then
Then
To sum up, the application difference and other current sensors in the prior art, it is contemplated that one-dimensional magnetoresistive sensor has heightCan the wide advantage of integrated level, high sensitivity, small size, cheap, small temperature drift, measurement range, therefore, the application passes through vertical distributionTwo one-dimensional magnetoresistive chips acquire magnetic vector of the conducting wire to be measured at magnetoresistive chip position respectively, in conjunction with x-axis One-Dimension MagneticResistance the distance between chip 2 (or could also say that the one-dimensional magnetoresistive chip 3 of y-axis) and the center of circle of conducting wire to be measured and Biot-Sa are cut downYour law can obtain the current value of conducting wire to be measured, so that the volume of current in wire measuring device and preparation cost are low,It is easily installed, and temperature drift is small, high sensitivity.
On the basis of the above embodiments:
As a kind of preferred embodiment, when a point of conducting wire to be measured and shell 1 is tangent, main control module is also used to rootThe pre-determined distance of preset according to the one-dimensional magnetoresistive chip 2 of x-axis to shell 1, preset to point of contact distance, be converted to digital quantityThe magnetic vector of x-axis direction and the magnetic vector in y-axis direction obtain wire cross-section area to be measured；
Wherein, the center of circle of preset, point of contact and conducting wire to be measured is point-blank；The one-dimensional magnetoresistive chip 2 of x-axis and shell 1Preset place straight line and the preset of shell 1 and the place straight line in the center of circle of conducting wire to be measured it is vertical.
It requires to select according to economic current density in GB/T 3485-1998 " evaluation enterprise's rational utilization of electricity fire protection technology "Wire cross-section area, current in wire is excessive easily to cause conducting wire to overheat, and destroys the insulation characterisitic and electrical characteristic of conducting wire.Work as power trainWhens system carries out dynamic compatibilization, overload characteristic test etc., it is thus necessary to determine that wire cross-section area.
The control module 5 of current in wire measuring device provided in this embodiment can also obtain wire cross-section area to be measured, beUnderstanding of the aspect to the present embodiment, is described the present embodiment below with reference to an example:
Referring to figure 2., Fig. 2 is provided by the invention a kind of to obtain the electric current of conducting wire to be measured using Biot-Savart lawThe schematic diagram of value.
Assuming that the electric current of conducting wire to be measured is I, radius is unknown, and conducting wire to be measured abuts current in wire measuring device, and O point isThe contact point (namely point of contact) of current in wire measuring device and conducting wire to be measured, A point be current in wire measuring device central point (Preset i.e. in the application), C point be the one-dimensional magnetoresistive chip 2 (or the one-dimensional magnetoresistive chip 3 of y-axis) of x-axis position, 3 points of AOBPoint-blank, the distance between AC l is it is known that setting the distance between AO, BO, BC is m, r, d respectively, wherein known to the value of m.The conducting wire can be directly measured in the magnetic field strength of C point, respectively B by twin shaft magnetoresistive chipxAnd By, then:
R value can be calculated by above formula, are as follows:
Sectional area of wire S can be calculated are as follows:
Examples detailed above is one of the present embodiment, extend also to conducting wire to be measured not with current in wire measuring deviceAgainst the case where, principle is identical as the principle of above-described embodiment.
As it can be seen that through this embodiment, staff can know each wire cross-section area to be measured, be conducive to it is subsequent according toEconomic current density selects wire cross-section area.
As a kind of preferred embodiment, ADC module 4 is double channel A/D C.
Due to the magnetic vector B for the x-axis direction for needing to export the one-dimensional magnetoresistive chip of x-axis 2xAnalog-to-digital conversion is carried out, is neededTo the magnetic vector B in the y-axis direction that the one-dimensional magnetoresistive chip of y-axis 3 exportsyIt carries out analog-to-digital conversion and therefore needs exist for two ADC,Double channel A/D C has been selected in the present embodiment, compared with two single channel ADC, integrated level is high, and it is small in size, it further reduces and leadsThe volume of line current measuring device.
As a kind of preferred embodiment, further includes:
The first amplifier being set between the output end of the one-dimensional magnetoresistive chip 2 of x-axis and the first input end of ADC module 4,It is amplified for the magnetic vector to x-axis direction；
The second amplifier being set between the output end of the one-dimensional magnetoresistive chip 3 of y-axis and the second input terminal of ADC module 4,It is amplified for the magnetic vector to y-axis direction.
Signal processing is carried out in order to facilitate control module 5, improves signal processing precision, in the present embodiment, is also provided with theOne amplifier and the second amplifier, for being amplified respectively to the magnetic vector of x-axis direction and to the magnetic vector in y-axis directionIt amplifies.The first amplifier and the second amplifier in the present embodiment can with but not only limit is the amplification based on operational amplifierCircuit.
As a kind of preferred embodiment, further includes:
It is set on shell 1, the fixation device 6 for being fixed on conducting wire to be measured on shell 1.
Specifically, current in wire measuring device provided in this embodiment further includes the fixation device 6 being set on shell 1,For conducting wire to be measured to be fixed on shell 1, to guarantee that conducting wire to be measured will not tamper, the magnetic vector of x-axis direction ensure thatWith the measurement precision of the magnetic vector in y-axis direction, and then the measurement precision of the current value of conducting wire to be measured ensure that.As oneKind preferred embodiment, fixed device 6 are U-shaped buckle.
Specifically, fixed device 6 can be U-shaped buckle, and U-shaped buckle has the advantages that structure is simple.Certainly, consolidating hereDetermining device 6 can not also particularly be limited herein with other kinds of fixed device 6, the present embodiment.
As a kind of preferred embodiment, Open Side Down for U-shaped buckle, and a port and shell 1 of U-shaped buckle are hinged,Another port is detachably connected with shell 1.
As a kind of preferred embodiment, shell 1 is equipped with and the mutually matched inner concave of conducting wire to be measured.
Specifically, referring to figure 3., Fig. 3 is a kind of conducting wire electricity for being provided with the U-shaped buckle that Open Side Down provided by the inventionThe structural schematic diagram of flow measuring apparatus.
Before placing conducting wire to be measured, the detachable port of U-shaped buckle is not connect with shell 1, is placing conducting wire to be measuredAfterwards, the detachable port of U-shaped buckle is connect with shell 1, and conducting wire to be measured is fixed on shell 1.In addition, in order to furtherConducting wire to be measured is fixed, is additionally provided with inner concave on shell 1, the inner concave and conducting wire to be measured cooperate.
As a kind of preferred embodiment, U-shaped buckle is the Elastic buckle of opening upwards.
As a kind of preferred embodiment, U-shaped buckle is plastic buckle.
Specifically, U-shaped buckle here can also be the Elastic buckle of opening upwards, and the length of the opening is less than to be measured leadThe diameter of line, when placing conducting wire to be measured, since Elastic buckle has elasticity, which can become larger, be placed into conducting wire to be measuredAfter going, opening can be restored as former state.Compared with the Elastic buckle that Open Side Down, the structure of the U-shaped buckle is simpler.
Here U-shaped buckle can with but be not only limited to plastic buckle, on the one hand, plastic buckle insulation reduces to conducting wire electricityInfluence when flow measuring apparatus measures；On the other hand, the lighter in weight of plastic buckle further reduces current in wire measurement dressThe weight set.
Referring to figure 4., Fig. 4 is a kind of flow chart of current in wire measurement method provided by the invention, is applied to as above-mentionedIn the current in wire measuring device of embodiment, this method comprises:
The one-dimensional magnetoresistive chip of S11:x axis measures the magnetic vector of the x-axis direction of conducting wire to be measured, and the one-dimensional magnetoresistive chip of y-axis is surveyedMeasure the magnetic vector in the y-axis direction of conducting wire to be measured；
The magnetic vector of x-axis direction is converted to digital quantity by analog quantity by S12:ADC module, and the magnetic field in y-axis direction is swearedAmount is converted to digital quantity by analog quantity；
S13: control module is according between Biot-Savart law, the one-dimensional magnetoresistive chip of x-axis and the center of circle of conducting wire to be measuredDistance is converted to the magnetic vector of x-axis direction of digital quantity and the magnetic vector in y-axis direction obtains the current value of conducting wire to be measured.
Above-described embodiment please referred to for the introduction of current in wire measurement method provided by the invention, the present invention is herein no longerIt repeats.
It should be noted that in the present specification, relational terms such as first and second and the like are used merely to oneA entity or operation with another entity or operate distinguish, without necessarily requiring or implying these entities or operation itBetween there are any actual relationship or orders.Moreover, the terms "include", "comprise" or its any other variant are intended toCover non-exclusive inclusion, so that the process, method, article or equipment for including a series of elements not only includes thoseElement, but also including other elements that are not explicitly listed, or further include for this process, method, article or settingStandby intrinsic element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded thatThere is also other identical elements in the process, method, article or apparatus that includes the element.
The foregoing description of the disclosed embodiments enables those skilled in the art to implement or use the present invention.Various modifications to these embodiments will be readily apparent to those skilled in the art, as defined hereinGeneral Principle can be realized in other embodiments without departing from the spirit or scope of the present invention.Therefore, of the inventionIt is not intended to be limited to the embodiments shown herein, and is to fit to and the principles and novel features disclosed herein phase oneThe widest scope of cause.